Cretaceous Lenisaurgy
by Spagthesis
Summary: Lisa sends Leni way back in time for a risky, and over the top sexual experiment. Rated M for ridiculously lewd.


**Author's note: Another one of those cases where I tried something super weird. It's gimmicky, but I got the idea from the whole dinosaur Leni joke. (The way she walks with her hands pointed down.) Regardless, I did it and I have to accept it. Originally posted on my pastebin on 7/1/18.**

* * *

Lisa was sitting alone in her room going through her file cabinet. She had folders filled with experiment ideas, some either accomplished, failed, or yet to be executed.

During searching, she discovered one that she recalled intrigued her. A little something she cooked up months ago, but never attempted. It was a pretty bold and risky project. Time travel to the cretaceous era. She's dealt with the subject before, and still had her time machine stashed away in her closet, so it wouldn't be entirely impossible to pull off.

However, that's just the easy part. The idea she had in mind was absolutely sick and twisted. It started after realizing something from previous research on dinosaurs, she's never actually seen much information about their genitalia, or how they procreated those many years ago.

The creatures themselves no matter what type were fascinating to her. All those fossils she's seen in museum visits, knowing they were once a living beast. It eventually left her desiring to see the process of conception, or at least sexual intercourse. This needed to happen, even if not by the book.

Lisa considered going back in time alone. For various reasons, she abandoned that idea. Her life, and the future would be at risk, alongside the fact it wasn't guaranteed that she would find what she's looking for. Not even with the camera she recently installed onto her time machine either, especially seeing how she had no way to control it while in the past.

Through doubts of being able to catch dinosaurs in the act of mating in person, and realizing this was a two man job, she took a much darker turn. Instead of them having sex with their own species, why not with one of her fellow human beings? It would be a step up, plus she had plenty of options to choose from as is.

While thinking about it, Lisa found exactly who to use, Leni. There is simply no better choice for this in terms of physical development, intelligence and general behavior.

Looking to see this plan through, the genius got to work right away. She was aware of the physical dangers her test subject may face, though that never stopped her from using people before. Given the threat of hostile dinosaurs coming into play, she planned to counter them with the power of lust, ensuring safety, and sex in one go. It is completely ideal, but not foolproof yet.

It required quite some time, but using female DNA samples and some scientific magic, Lisa created a unique spray that was layered with sex pheromones. An experimental type engineered to boost the libido of human females and attract males of different species.

She thought about testing it on herself first before sending her subject out on the wild mission. It would be beneficial to see how long it triggers and lasts for. She could note the reaction that say, Charles, Cliff or any of the pets would have to her.

Although, the young girl discarded idea after realizing she would just be reducing herself to the test dummy.

Willing to delve into antiquity, Lisa stood up from her chair and huffed. "Time to go."

She walked out of her room to find Leni.

Conveniently enough, she happened to be strolling on by the door.

"Greetings, Leni, what are you up to by chance?" Lisa asked, trying to sound casual, not that her big sister would be suspicious of her for any reason.

"Oh, I'm just going to the mall. Do you want anything?" Leni asked sweetly.

Lisa pondered for a split second before responding. "No, but say, since you're going, I could transport you there in a flash if you'd like."

"A flash?" Leni questioned.

"Umm, nothing." She grinned widely. "Follow me, I'll take you to the mall."

Leni smiled and accepted her offer. "Thanks, Lisa!"

A few steps later, Lisa made it back to her room with the girl.

She shut and locked the door for the sake of keeping privacy.

Leni stood by as the young girl activated her time machine and set the year dial to get things started.

"The mall is right through here, but before you go, I have a gift for you." Lisa said.

"What is it?" Leni asked, her excitement peaking. What could her little sister possibly have for her?

"It's a special perfume I created." Lisa assured, smiling as she held it.

Leni gasped. "Wow!"

Lisa handed it over, watching as her sister doused herself with the spray, probably using too much in fact. There was a wonderful fruity aroma to it, totally appropriate for a girl like her. She loved maintaining her womanliness in anyway she could, perfumes, makeup, dresses and anything like that always made her day.

Leni became enamored by the scent, finding it incredibly refreshing.

It excited every inch of her. She felt an odd burning sensation inside, one that seemed to crank her energy up. It even made her feel somewhat needy, and funny in unusual places.

Lisa distanced herself from her to avoid making contact with the substance, remembering not to become her own test dummy.

"How do you feel?" She asked.

"I feel great! This perfume is totes sweet!" Leni squealed happily, setting the perfume bottle on a dresser.

"I'm glad it pleases you. Now, put this on." Lisa ordered, handing her an earpiece mic.

"Why do I need a microphone?" Leni questioned.

"It's uhh, so we can communicate when you get to the mall. I've mapped out some suitable shops with great deals!" The young girl exclaimed.

"Oh, okay!" Leni said, not putting much thought into it while she slipped on the earpiece. Instead, she was thinking more about what to buy when she arrived. There's a beautiful pearl necklace somewhere with her name on it.

"Alright, please step on through there and you'll be transported to your desired destination." Lisa pointed over to the machine eagerly.

Optimistic as ever, Leni sauntered joyfully inside the portal.

She arrived sixty six million years in the past, the cretaceous period of earth. Orange skies, red hot soil, and ancient rocks surrounded the environment. It was completely barren, unlike the suburbs of Royal Woods. Completely foreign to anything anyone had ever seen. Yet, the girl needed to adjust to it for the time being, which may prove to be difficult.

That aside, Leni wandered around the land confused.

"This doesn't look like the mall." She said.

Lisa angled the camera, recording her movements and displaying it on her projector, scouting out if she could see any dinosaurs nearby.

Meanwhile, the unforgiving sun kept on burning.

Leni felt every single ray of light, it had to be at least over a hundred degrees.

"It's so hot." She moaned. "There's like, no a/c in this mall."

Then suddenly, a fierce, rumbling noise hit her ears. The ground quaked intensely as dust kicked up right before her eyes.

Curiosity getting the best of her, Leni ambled towards the sound to see what it was.

Soon enough, she found out.

A little rogue of three velociraptors appeared, howling in unison and charging towards the girl with eyes seemingly set to kill.

Leni spotted them and stopped dead in her tracks.

Unsure of why she didn't fear them, she remained still as they came closer.

The way she limped her wrists showed signs of harmlessness. If she's lucky, they'll do her right.

Lisa spectated the whole event.

She began sweating, becoming anxious. If the pheromones didn't work, the girl would be a goner. Though she needed to see it if pulls off, even if it meant gambling with her sister's life.

The dinosaurs got in range and encircled Leni, swooping their heads down as they moved, getting a sense and feel of the mysterious woman in front of them.

They smelled her, inhaling her divine, arousing fragrance. ...And immediately changed their game plan from feed to breed.

They were all somewhere around six feet tall and one hundred fifty pounds, give or take. Compared to the blonde in front of them, who seemed to be about five feet, six inches tall and one hundred ten pounds, a noticeable size difference.

Leni was also outmatched greatly. Could she really handle all of them?

Whether she could or not didn't click with her as she got an eyeful of their bodies, seeing their dark green scales, and quite muscular proportions. Their lengthy tails stuck up in the humid air as they glared at her.

Her attention soon wandered to what they were packing between their bulky legs, some very vein riddled, and solid nine inches of cretaceous cock.

"Hmmm, it appears their penises are quite large, and their testicles seem to be internal..." Lisa mentioned to herself quietly.

She glued her eyes on the scene, keeping herself focused while making sure this goes as planned.

Leni drooled, feeling hypnotized by their rods.

She smiled, gesturing them to come closer and get it on.

Lisa muted her mic and spoke. "Now to start the interspecies mating process."

With the secret camera zoomed in spectating Leni's every move, she was set to go.

Using his teeth, one velociraptor pulled her undies down, dropping them around her ankles and into the dirt.

The other lifted her dress off, holding it in his teeth and doing likewise.

The last dinosaur handled her pumps by snagging them off her petite feet and tossing them aside.

Seeing now that their new lady friend is nude, they could really crank things up a notch.

Leni's heart skipped a few beats as her pulse increased.

Her legs quivered, she felt so hot, even more than before.

Showing no fear, and feeling the effects of that perfume, the girl lost it. She blocked out everything else, and focused on what she truly yearned for.

Leni submitted to them by laying down on a nearby boulder. It was angled perfectly enough for them to mount her.

Determined to get it on, she spread her legs and revealed her fresh womanhood to the horny velociraptors.

They hovered closer to her.

One capitalized by sticking it's head between her legs and getting a whiff.

His warm breathe gently blowing across her sweet spot caused the girl to twitch. Teasing never hurt, but she anticipated, prayed that they would just sexually ravage her.

Leni's prayers were answered as that same dinosaur hunched up, sending his small arms onto her shoulders.

His nails unintentionally grated her shoulder blades as his weight pinned her.

With a big smile, she peered down, seeing his throbbing penis approaching her slit.

"Come on, sweetie." She mewled.

Holding her breath, Leni braced herself for the incoming rod.

The head pierced her hole slowly, causing her to grunt.

He went deeper by the second, getting every single inch inside. The girl always wanted to be over six feet tall.

All the way in, he licked Leni's flustered face before pulling out.

The feeling of his penis sliding out in a swift movement caused her to grunt.

After getting a brief feel of her vagina, the velociraptor went penetrated her again.

He jerked his hips forwards, setting a good motion, and history as he commenced breeding a different species. One that was far more advanced, physically as opposed to intellectually.

His size was almost too big, but Leni endured it anyways. She found herself hardly caring that her cherry had been popped as the dinosaur penetrated her consistently.

She viewed each thrust joyfully, taking note of the head causing her lower abdomen to expand a little, stuffing her profoundly.

Feeling bold, and eager for the next boy, she assisted him by massaging his member while he pounded her for minutes.

Only to subsequently unload after her extra attention, pouring a wad of semen deep inside her womb, overflowing her walls with his thick, ancient seed.

Lisa could see, and hear the sound of it all squelching. For the first time ever, she felt nauseous during an experiment. Although, she kept her microphone muted and dealt with it for the sake of science.

"Good boy..." Leni cooed as she felt the great amount of velociraptor cum spill inside her.

Watching it ooze between her soft lower lips, she continued. "Next."

The second dinosaur walked up, getting into the same position as the previous one did.

Ready to bone, he pierced her hole, feeling the leftover seed and wetness of her walls melt on his member, along with creating a decent pace when he did so.

While Leni got plowed by him, the other two velociraptors moved in a little closer, huddling all over her personal space.

They showed teeth, almost like they were grinning about the gang bang.

There was no hostility between any of them as they possessed the same goal.

As she remained busy taking inch after inch of reptilian cock, the others started to lick her.

Their tongues swayed over her bountiful breasts that jiggled with each thrust.

They boobs flopped around uncontrollably, their tender nipples growing hard and prone to being loved.

One hunched over, licking Leni's neck and sending her overboard.

"Aaaah." She moaned, eyes squinting while enduring their complete affection.

Taking the additional pounding, Leni could really feel her skin scraping against the rock. It grated her back a bit, but she battled through it.

Ignoring the discomfort, she shifted her focus to her lower lips again, grinning as the second beast put in work.

"Don't stop." She yearned, watching his veiny member jam her vagina.

She brought a hand down to feel the vibrations of it entering and exiting her.

Following some consistent pushing, the poor creature couldn't handle holding it anymore.

The second dinosaur grunted heavily when he blew his load deep inside Leni.

He arched his neck back and poured almost every drop that he had.

The girl was ecstatic upon feeling the double dosage of semen oozing in her. She wanted even more.

"Last one, I hope..." Lisa uttered.

Keeping still, she watched as the dinosaur pulled out of her and rotated, leaving the third beast up next.

Leni gestured to him, seeking another helping of semen.

The velociraptor lunged forward, balancing himself by keeping his claws on her shoulders just as the others did.

He shifted upwards, getting his rod ready and following up with a big plunge.

The entrance was quite slippery, seeing how she had already gone through two of them. Regardless, he started humping, thrusting inside of the girl with great force.

He slammed in and out to the sounds of squirting juices.

Leni arched her back up, her eyes fluttering as she welcomed every inch of him.

She felt her vagina quiver and leak as his dick buried itself inside her.

She clenched up somewhat and glared down, seeing the beast pound her passionately while hearing his grunts become more hoarse with each penetration.

Currently, the other two dinosaurs licked her burning hot skin. One gave attention to her breasts again as the other focused her face.

Leni managed to purse her lips, kissing one of them amidst the sexual chaos.

As the beast pushed forward, she became exposed to his teeth, tongue and unfortunate prehistoric halitosis.

The girl ignored the latter, and surrendered her mouth to him.

The difference between the size of their tongues was giant, much to her delight. She accepted the little oral tango happily.

All the intense action going on eventually sent her overboard.

"Ohhhhh!" She whimpered at an ear piercing rate.

Lisa shuddered hearing her, and frantically lowered the volume of her headset.

Despite briefly being shook up, she continued watching her get boned silly, occasionally looking away here and there to make sure nobody was near the hall. The sooner she gets her sister back home the better.

The third velociraptor pounded his heart out, putting even more power into his thrusts than before, and making sure he absolutely breeds the girl on par with his allies.

Leni's chest tightened, sensing both of their limits being reached.

Another wave of dinosaur cum got sent and drenched her vaginal walls.

She winced while feeling the final shots of it in her womb, realizing it was significantly hotter than the first two loads already inside her. The combined, thick amounts practically suffocated her womanhood, flooding and overwhelming it simultaneously.

As he pulled out and gave her space, the girl viewed the aftermath of the sex. Her flower was bloody red, and painted with love juices all around it. Most of the cum made it inside her core, but quite a bit remained on the lips.

Taking a deep breath, Leni stumbled on up, bending down as she touched herself.

She got an even closer look, then pried her vagina open, causing a massive amount of semen to pour out.

It steamed when it made landed on the hot dirt below.

Realizing she didn't every bit out, she pushed, resulting in a loud, vile queef as the other bits of cum fell out.

Lisa's faced turned green, but still kept herself together and managed to avoid puking.

Before she got to speak however, Leni made another bold, lustful move.

While getting another glance at the dinosaurs, she witnessed their members hanging freely for her viewing pleasure. Flaccid, yet dripping with fluids still. Once again, she wanted more, figuring that a taste test wouldn't hurt.

Intent on getting even more of their seed, Leni got down on her knees in front of them, not even caring about the feeling of the rough ground on her soft skin.

The velociraptors understood the hint and surrounded her again.

They wobbled a little back and forth as they did, swaying their goods around the girl's hungry face.

With her tongue out and ready, Leni multitasked to all hell.

She gripped her hands on two cocks, and consoled the remaining one using her mouth.

She bobbed her head wildly, sucked passionately, and jerked her hands with great force.

After spitting a single rod out, Leni alternated around a bit, making sure each creature got a feel of her sweet mouth and firm hands. The consistent slimy feeling between her fingers and lips excited her substantially.

Eager, she continued the motion.

Lost in the sensation, the pack huddled even closer, surrounding her further and letting their penises rest on her face.

Being literally covered in dicks, Leni opened up her mouth up like she was undergoing dental surgery.

The two other hard members found their way inside, colliding together, meeting the girl's wet tongue and throat.

Leni closed her mouth to relish the moment.

She sucked calmly and ran her tongue haphazardly across each of their tips.

Leni moved her hands around, ensuring she got to touch them all.

She gasped while she stroked them beyond belief.

Her arms grew sore as she handled their members passionately, but she wasn't going to give up. She became too far lost in lust to comprehend things. She needed their cum inside her no matter what, ultimately desiring to have both of her holes filled.

Feeling it was time to speak, Leni plopped her mouth open and freed the multiple rods.

She choked, letting a long strand of drool and semen drip onto her bare thighs.

Leni looked up, eyes aflame with carnal lust. This was it, the end of her... exciting shopping spree.

"Give me that dinosaur cum!" She exclaimed, grinning.

Lisa cringed hearing those words.

She kept seated, digesting the action on her screen and through her headset. It was very unsettling to listen and see, but pretty soon it would be all over. That is, if she speaks up this time around.

The blonde titled her head back slightly and opened her mouth wide again.

Leni's tongue waddled side to side as she closed her eyes. Seeing is one thing, yet as of this moment she preferred focusing on the feeling of cum drenching her, storming her tongue, mouth and sliding into her throat.

After some loud, bestial grunts, the velociraptors came in unison.

Their penis heads spurted many ounces of fresh semen on the girl. It all poured in or on her mouth, lips and face, but some of it dripped down her neck.

Feeling the flow cease, Leni peeked an eye open to make sure they were done.

Confirming that, she sealed her mouth, her cheeks puffing up from the abundance of seed.

Semen seeped through her lips as she smiled.

Not wanting to lose any of it, Leni tried gulping it all down.

The wad of hot cum in her throat initially caused her to choke, though after some brief back slapping she successfully swallowed every drop.

She let out a small gasp, wiping her mouth and licking any strands straight off her fingers.

Leni's face became a complete mess afterwards, being doused with white cream and quite obscene.

Regardless, the girl got herself up and stretched her arms out.

She smiled, happy and content with that literal hot sex.

But feeling pretty fatigued, she didn't attempt to make a go for round three, there was no telling if her buddies would be able to blow another load as is.

Instead, Leni went and picked up her clothes.

Taking a moment, she slipped each article of clothing back on.

Once her panties, shoes and dress were set, she patted herself a little, thinking about how much of a dirty girl she is. Literally as opposed to figuratively.

Lisa turned her mic on and spoke urgently. "Leni, I need you to return through the portal now."

Hearing her words, Leni glanced behind her at the now lit up device.

She began to hesitate.

"What about my friends?" She asked sorrowfully.

"They'll be fine..." Lisa insisted, nervously biting her lip. Potential emotional connections weren't something she even thought about it. She didn't quite have a backup plan if her sister refused to listen. Knowing her though, that was highly unlikely.

Leni sighed, looking up at the pack of dinosaurs who stared back at her.

With her arms wide open instead of her legs, she ran towards them.

"I'm gonna miss you guys so much!" The girl sniffled while initiating a group hug.

They returned their affection by nuzzling their heads into her breasts and shoulders.

The velociraptor gang licked her flustered face again as a means of healing her distress.

When Lisa witnessed the embrace, Leni's compassion made her feel tingly, chilling her skin completely out. A hard task to accomplish seeing how she isn't one to sympathize with her fellow humans much. A big heart and gentle soul makes her one of a kind, no doubt. Even despite being screwed up by lust, she somehow retained her true self.

Letting go regretfully, Leni turned around and walked towards the portal.

Each step became harder as she moved.

Before going inside, she took another look back and waved goodbye to the velociraptors.

Doing her hardest to avoid flat out bawling, Leni sucked it up and stepped in through the device.

In a flash, she appeared in Lisa's room.

Luckily, for their sake, everything remained the same as it was when she left.

Leni glanced at Lisa while taking a step forward and wiping her eyes.

"Are you alright?" She asked.

"I'm sad, I really liked them." The girl rubbed her blushed face, trying to get herself together.

"I see..." Lisa responded, feeling a tad guilty, and uncertain of what to tell her.

Twiddling her fingers anxiously, Leni asked. "Can I go visit them again?"

Lisa wasn't surprised by her asking. However, she could only hope that was mainly the perfume talking and not herself.

To avoid upsetting her, she complied. "I suppose in a few days..."

The genius felt uneasy after experiencing that. Her sister's enthusiasm wasn't necessarily expected or guaranteed. Nonetheless, at least she didn't get her mauled, plus she managed to pull off her experiment with no harm done. It seemed to have all worked out, that was quite rare for her, given the record of scientific endeavors literally blowing up in her face.

Leni's mood did a complete one eighty.

"Yay! I can't wait to play with my big dinosaur friends again!" She cheered.

Being the hugging type, Leni couldn't resist as she bent down and embraced her.

"Thank you so much." She added, strengthening her grasp.

"You're welcome." Lisa said, getting a faint whiff of what she presumed was all that velociraptor semen, the odor being as vile as one would imagine. Although, she's sure hoping nobody else gets to smell it.

Leni ended her affectionate hug.

"I feel kinda icky, I think I'll go brush my teeth and take a hot shower." She spoke, fluffing her blonde hair out while handing the microphone back to her sister.

"Excellent idea." Lisa responded, nodding. That's probably the first time she's ever told her that. And it definitely was warranted.

The girl smiled at her happily, then started leaving the room.

"Wait." Lisa said.

"Yes?" Leni asked, curious by her tone.

"Never speak of this to anyone else. If you do, they'll try and... steal your velociraptors from you. Those creatures are y-your sexual property." She stated, shuddering while mentioning that last part.

"Got it. Those boys totes belong to me!" Leni said smugly.

"Precisely." She replied, feeling the sweat on her skin cool.

Leni had a big mouth in many ways, but with that taken care of she could relax somewhat.

However, Lisa wasn't too keen on sending her back again. But maybe some more research can help? In any case, she had a lot to think about.

Leni marched out the door, doing her limp-wristed hand walk, and having totally forgotten about going to the actual mall on her way down the hall. ...She technically did get a pretty nice pearl necklace after all.

Happy as ever, blissfully dumb, and filled up with cum, she arrived inside the bathroom to clean herself up.

Seeing the coast clear, Lisa went ahead and stashed the recordings of the insane experiment away in a safe alongside the perfume despite gifting it to Leni. The fact that it worked like a charm would render it dangerous in her sister's hands.

* * *

When the clock struck midnight hours later, Lisa laid awake going over everything that went down in her mind. Normally, she was pretty desensitized to most things, seeing how much she truly knew about life in general.

However, what she put Leni through might have the been craziest thing she's ever done. Her sister was both the first woman to travel back in time, and to not only see, but to have sex with dinosaurs. It seemed unreal. Yet, she had far too much footage of it, stuff she would have to power through eventually. She mostly wanted to see if it could be pulled off, and it certainly was.

At some point, Lisa ended up closing her eyes and falling asleep.

Her train of thought didn't seem to fade once she did, resulting in a dream.

She walked to Leni's room to pay her a visit.

With the push of a door, she stumbled onto something even she never expected.

The girl was completely naked, lying on her side as a bunch of baby velociraptors roamed around on her bed.

Lisa saw green eggs shattered and scattered about while they walked.

The babies howled, yearning for their mom's love and affection.

"Babies, Mommy's got some milkies for you!" Leni said excitedly.

The little dinosaurs headed over to her as her boobs slumped over on the sheets.

All six of them took turns breastfeeding, scoring any bit of milk they could get.

Leni felt pretty determined to make sure her kids grow up big and strong, just like their father, whichever velociraptor it was.

Without averting her gaze or speaking, Lisa back pedaled out of the room in a rush, taking in fact that she made the biggest mistake of her life, causing something that would be nearly impossible to explain.

As she kept on moving, she tripped on one Lily's toys in the hall, sending her falling flat backwards and knocking her out cold.

Lisa awoke, sitting up frantically and sweating like she was in a sauna.

She reached for her glasses, putting them on and glancing at the clock to see the time. It was 1:45am.

The genius shook her head, realizing it was only a nightmare.

Pulling herself together, Lisa laid down and found more mental images cluttering her mind right before whispering to herself. "On second thought, no more trips to the mall, Leni."


End file.
